1. Field of the Invention
The present invention generally relates to a machine in which a log is transported through the machine center for chipping or sawing a slab from both sides of the log in a single pass and/or sawing a side board or flitch from one or both sides of the log in a single pass and/or sawing multiple boards by reciprocating the log through the center of the machine. This invention relates specifically to the center carriage feed system having a bottom carriage and a top carriage in which the bottom carriage supports the log continuously for its full length and the top carriage utilizes hold down bars or dogs that engage the top of the log. The bottom carriage includes a log supporting vertical member having a transverse member at its lower end provided with a wheel at each end to engage widely spaced parallel tracks. One of the wheels and tracks are of V-shaped configuration to stabilize and guide the vertical log supporting member to reduce lateral deflection. The other track and wheels are flat. The wheels and tracks effectively support the log throughout its length and during its reciprocatory movement.
2. Description of the Prior Art
Existing machines of the above type are supported by a continuous vertical log supporting member engaging the bottom center of the log with the supporting member having a plurality of aligned V-shaped wheels at its lower end directly aligned with the bottom center of the log. These wheels engage a single inverted V-shaped track also aligned with the bottom center of the log so that the log supporting member can pivot or be laterally deflected about the single centrally located track even though top dogs hold the log in opposed relation to the log supporting member.
The prior art does not utilize a supporting structure for the log equivalent to the structure of this invention in which the log supporting member includes a vertical member which continuously engages the log throughout its length with the log supporting member being thin in cross section to allow chippers and/or saws to be set to a minimum cant thickness of 3 inches with the vertical support member being rigidly connected to a wide bottom carriage below the chippers or saws. The bottom carriage includes laterally spaced wheels engaging spaced tracks oriented in laterally spaced relation to both sides of the bottom center of the log to provide substantially greater stability as compared to the existing support structure for the log in which aligned wheels engage a single track oriented in alignment with the bottom center of the log.